In micromirror devices each having a light transmissive substrate, a semiconductor substrate; and a reflective deflectable mirror plate disposed therebetween, incident light to be modulated by the mirror plate travels through the light transmissive substrate and impinges the reflective surface of the mirror plate. The mirror plate switches between the ON and OFF state so as to reflect the incident light into different spatial directions. During switching, the mirror plate may contact the surface of the light transmissive, resulting in electrical short when the light transmissive substrate comprises electrode.
Therefore, what is needed is a method and apparatus to electrically isolating the mirror plate from the light transmissive substrate.